Coherency directory entry allocation based on eviction costs

A method, comprising:

• associating each region of a plurality of regions of a coherency directory with a different corresponding processor core of a plurality of processor cores, each of the plurality of regions comprising a corresponding plurality of entries to store coherency information for corresponding memory addresses;
• monitoring a miss rate for each of the plurality of regions, the miss rate for a region indicative of a number of times the corresponding region has indicated that it does not include an entry targeted by a corresponding cache probe;
• and
• adjusting a number of entries allocated to each of the plurality of regions based on the monitored miss rates.

A processor comprising:

• a plurality of processor cores;
• a cache;
• a coherency manager to manage coherency at the cache, the coherency manager comprising:
• a coherency directory comprising a plurality of regions associated with different corresponding ones of the plurality of processor cores, each of the plurality of regions comprising a corresponding plurality of entries to store coherency information for corresponding memory addresses;
• and
• a control module configured to:
• monitor a recall cost for each of the plurality of regions, the recall cost for a region indicative of a resource cost of reallocating entries of the coherency directory to different regions;
• and
• adjust a number of entries allocated to each of the plurality of regions based on the monitored recall costs.